During medical intervention procedures one or more intervention devices may have to be accurately positioned within a region of interest within a patient. For example e.g. during a cardiac catheterization a wire tip may have to be positioned at a precise location within a vessel system. In order to help a physician in such positioning, medical imaging devices are typically provided for displaying an image representation from which the physician may derive information about both the patient's anatomy within a region of interest and the current position of the intervention device.
Conventionally, X-ray imaging devices are used to provide a fluoroscopy image or a sequence of fluoroscopy images during the intervention procedure. In the fluoroscopy image(s), the physician may observe the actual position of the intervention device as such intervention device typically comprises X-ray opaque portions.
The acquisition of a plurality of X-ray fluoroscopy images implies that the patient is subject to an essential X-ray exposure. However, an X-ray dose transmitted through the patient's body should be as low as possible. In order to reduce the X-ray exposure, U.S. Pat. No. 7,340,033 B2 proposes to use an X-ray image acquisition device comprising an adjustable collimator, to determine a region of interest from an acquired X-ray picture and to adjust the collimator thereon. Therein, the region of interest can be chosen to be large enough for the irradiation field to cover all those positions of an organ of interest that occur as a result of heartbeat and/or respiration.
Furthermore, X-ray fluoroscopy images may suffer from a poor contrast such that the patient's anatomy may be difficult to observe in such fluoroscopy images and it may be difficult to determine where the intervention device is positioned relative to the patient's anatomy.